Learn about mites that live and die on your face, in this episode of Gross Science from NOVA. Face mites, or Demodex mites, are very common; most healthy adults have at least a few. People usually acquire their first mites during childhood. The mites live in hair follicles or sebaceous glands and crawl onto the skin surface to mate. Each mite stores its waste in its abdomen; when the mite dies, feces leaks over the skin surface. Some scientists think that the bacteria in the mites' feces could be related to certain skin conditions like rosacea or blepharitis. This resource is part of the NOVA: Gross Science Collection.